Pre-engineered frame portion and method of use therefor

ABSTRACT

A vehicle chassis includes a structural frame having a frame portion that partially defines an open space and that has a predetermined configuration such that the open space maintains a predetermined amount of spatial integrity in the event of a horizontal impact to the vehicle chassis. The frame also includes a frame component operatively connected to the frame portion that further defines the structural frame. The open space provides a protected packaging space wherein certain critical chassis components are placed. The frame portion configuration provides a pre-engineered protected area that may be used in a variety of structural frame configurations. Accordingly, a method for using pre-engineered frame portions is provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention is a Divisional application of U.S. applicationSer. No. 11/195,489 filed Aug. 2, 2005, which is a Divisionalapplication of U.S. application Ser. No. 10/358,996 filed Feb. 5, 2003.

TECHNICAL FIELD

This invention relates to pre-engineered frame portions for vehiclechassis, and more particularly to frame portions that define aprotective open space.

BACKGROUND OF THE INVENTION

Prior art vehicle structural frames must provide protection for variousvehicle system components in the event of an impact to the vehicle, andare therefore designed and tested to conform to various impact standardsand criteria. Typically, every new vehicle configuration requiresextensive engineering and validation efforts to ensure that thestructural frame of the new vehicle configuration will provide adequateprotection to vehicle system components.

Furthermore, new systems being developed for use in automotive vehiclesoften include components that are more complex and fragile than moreconventional vehicle system components. These new systems, such ashydrogen fuel cells, hydrogen storage systems, and drive-by-wiresystems, provide significant advantages over more conventionalautomotive systems, but may be more susceptible to damage in the eventof a vehicle impact. Engineering protected spaces within a vehiclestructural frame for such components may be significantly moreresource-intensive, and therefore more expensive, than engineering priorart vehicle structural frames.

SUMMARY OF THE INVENTION

A vehicle chassis includes a structural frame having a frame portionthat defines an open space. The frame portion has a predeterminedconfiguration such that the open space maintains a predetermined amountof spatial integrity in the event of an impact to the vehicle chassis.The structural frame also includes at least one frame componentoperatively connected to the frame portion to further define thestructural frame. The at least one frame component may be developed withlittle or no engineering and validation efforts directed to theprotection of the protected space because the predeterminedconfiguration of the frame portion is engineered and validated to complywith a predetermined standard or criterion for maintenance of thespatial integrity of the open space in the event of an impact to thevehicle chassis. Accordingly, the frame portion provides a protectedarea, i.e., the open space, in which sensitive and fragile vehiclecomponents may be located and protected from an impact to the vehicle,and the at least one frame component is an add-on that is configured togive the structural frame a size and shape suitable for an intended use.The frame portion is preferably a prefabricated frame module.

The vehicle chassis preferably includes at least three wheels rotatablymounted with respect to the structural frame, an energy conversionsystem mounted with respect to the structural frame and operativelyconnected to at least one of the at least three wheels, a steeringsystem mounted with respect to the structural frame and operativelyconnected to at least one of the at least three wheels, a braking systemmounted with respect to the structural frame and operatively connectedto at least one of the at least three wheels, and an energy storagesystem operatively connected to the energy con version system andmounted with respect to the structural frame. The frame portion definingthe open space provides an optimized area in which at least a portion ofat least one of the energy conversion system, energy storage system,steering system, and braking system is located.

A predetermined frame portion configuration may be advantageouslyemployed in structural frames of varying sizes and shapes to provide apre-engineered protected area for vehicle components and thereby reducethe engineering efforts required to develop each structural frame.Accordingly, a method of using a predetermined frame portionconfiguration is provided. The method includes assembling a firstvehicle chassis structural frame having a first frame portion. The firstframe portion defines a first open space, has a predeterminedconfiguration such that the first open space maintains a predeterminedamount of spatial integrity in the event of a load exerted on the firstframe portion, and partially defines the first vehicle structural frameThe first vehicle structural frame also has a first selection of atleast one frame component further defining the first vehicle structuralframe and operatively connected to the first frame portion such that thefirst vehicle structural frame has a first size and a first shape.

The method also includes assembling a second vehicle chassis structuralframe having a second frame portion. The second frame portion issubstantially identical to the first frame portion, defines a secondopen space, has a predetermined configuration such that the second openspace maintains a predetermined amount of spatial integrity in the eventof a load exerted on the second frame portion, and partially defines thesecond vehicle structural frame. The second vehicle structural framealso has a second selection of at least one frame component furtherdefining the second vehicle structural frame and operatively connectedto the second frame portion such that the second vehicle structuralframe has a second size and a second shape. The second size is differentfrom the first size, or the second shape is different from the firstshape.

The above objects, features, and advantages, and other objects features,and advantages, of the present invention are readily apparent from thefollowing detailed description of the best modes for carrying out theinvention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration in perspective view of a vehiclerolling platform according to an embodiment of the present invention;

FIG. 2 is a top view schematic illustration of the vehicle rollingplatform shown in FIG. 1;

FIG. 3 is a bottom view schematic illustration of the vehicle rollingplatform shown in FIGS. 1 and 2;

FIG. 4 is a schematic illustration in side view of a vehicle body podand rolling platform attachment scenario according to the presentinvention that is useful with the embodiments of FIGS. 1-3.

FIG. 5 is a schematic illustration of a vehicle body pod and rollingplatform attachment scenario, wherein body pods of differingconfigurations are each attachable to identical rolling platforms;

FIG. 6 is a schematic illustration of a steering system for use with therolling platform and body pod shown in FIG. 4;

FIG. 7 is a schematic illustration of an alternative steering system foruse in the rolling platform and body pod of FIG. 4;

FIG. 8 is a schematic illustration of a braking system for use with therolling platform and body pod of FIG. 4;

FIG. 9 is a schematic illustration of an alternative braking system foruse with the rolling platform and body pod of FIG. 4;

FIG. 10 is a schematic illustration of an energy conversion system foruse with the rolling platform and body pod of FIG. 4;

FIG. 11 is a schematic illustration of an alternative energy conversionsystem for use with the rolling platform and body pod of FIG. 4;

FIG. 12 is a schematic illustration of a suspension system for use withthe rolling platform of FIGS. 1-5;

FIG. 13 is a schematic illustration of an alternative suspension systemfor use with the rolling platform and body pod of FIG. 4;

FIG. 14 is a schematic illustration of a chassis computer and chassissensors for use with the rolling platform and body pod of FIG. 4;

FIG. 15 is a schematic illustration of a master control unit with asuspension system, braking system, steering system, and energyconversion system for use with the rolling platform and body pod of FIG.4;

FIG. 16 is a perspective illustration of a skinned rolling platformaccording to a further embodiment of the present invention;

FIG. 17 is a perspective illustration of a skinned rolling platformaccording to another embodiment of the present invention;

FIG. 18 is a side schematic illustration of a rolling platform with anenergy conversion system including an internal combustion engine, andgasoline tanks;

FIG. 19 is a side schematic illustration of a rolling platform accordingto another embodiment of the invention, with a mechanical steeringlinkage and passenger seating attachment couplings;

FIGS. 20 and 20 a show partial exploded perspective schematicillustrations of a rolling platform according to a further embodiment ofthe invention in an attachment scenario with a body pod, the rollingplatform having multiple electrical connectors engageable withcomplementary electrical connectors in the body pod;

FIG. 21 is a perspective schematic illustration of a skinned rollingplatform according to yet another embodiment of the invention, therolling platform having a movable control input device;

FIG. 22 is a top view schematic illustration of a prefabricated framemodule and a selection of frame components for use in assembling analternative chassis structural frame;

FIG. 23 is a top view schematic illustration of a rolling platformhaving an alternative structural frame including the prefabricated framemodule and selection of frame components of FIG. 22;

FIG. 24 is a top view schematic illustration of a rolling platformhaving yet another alternative structural frame including theprefabricated frame module of FIG. 22;

FIG. 25 is a top view schematic illustration of another prefabricatedframe module;

FIG. 26 is a top view schematic illustration of yet anotherprefabricated frame module;

FIG. 27 is a top view schematic illustration of yet anotherprefabricated frame module;

FIG. 28 is a top view schematic illustration of yet anotherprefabricated frame module;

FIG. 29 is a top view schematic illustration of yet anotherprefabricated frame module;

FIG. 30 is a top view schematic illustration of yet anotherprefabricated frame module and a selection of frame components; and

FIG. 31 is a schematic illustration of methods for advantageouslyemploying pre-engineered frame portion configurations to assemblevehicle chassis structural frames.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a vehicle chassis 10 in accordance with theinvention, also referred to as the “rolling platform,” includes astructural frame 11. The structural frame 11 depicted in FIG. 1comprises a series of interconnected structural elements including upperand lower side structural elements 12 and 14 that comprise a“sandwich”-like construction. Elements 12 and 14 are substantially rigidtubular (or optionally solid), members that extend longitudinallybetween the front and rear axle areas 16, 18, and are positionedoutboard relative to similar elements 20, 22. The front and rear ends ofelements 12, 14 are angled inboard, extending toward elements 20 and 22and connecting therewith prior to entering the axle areas 16, 18. Foradded strength and rigidity a number of vertical and angled structuralelements extend between elements 12, 14, 20 and 22. Similar to theelements 12, 14, 20 and 22, which extend along the left side of therolling platform 10, a family of structural elements 26, 28, 30 and 32extend along the right side thereof.

Lateral structural elements 34, 36 extend between elements 20, 30 and22, 32, respectively nearer the front axle area 16 and lateralstructural elements 38, 40 extend between elements 20, 30 and 22, 32,respectively nearer the rear axle area 18, thereby defining amid-chassis space 41. The front axle area 16 is defined in and aroundstructural elements 43, 44 at the rear and front, and on the sides bystructural elements 46, 48 which may be extensions of the elements 20,22, 30, 32 or connected therewith. Forward of the front axle area, aforward space is defined between element 44 and elements 50, 52. Therear axle area 18 is defined in and around structural elements 53, 54 atthe front and rear, and on the sides by structural elements 56, 58,which may be extensions of the elements 20, 22, 30, 32 or connectedtherewith. Rearward of the rear axle area 18, a rearward space isdefined between element 54 and elements 60, 62. Alternatively, the rearaxle area 18 or the rearward space may be elevated relative to the restof the structural frame 11 if necessary to accommodate an energyconversion system, and the frame may include other elements to surroundand protect an energy conversion system. The frame defines a pluralityof open spaces between the elements described above. Those skilled inthe art will recognize materials and fastening methods suitable for usein the structural frame. For example, the structural elements may betubular, aluminum, and welded at their respective connections to otherstructural elements.

The structural frame 11 provides a rigid structure to which an energyconversion system 67, energy storage system 69, suspension system 71with wheels 73, 75, 77, 79 (each wheel having a tire 80), steeringsystem 81, and braking system 83 are mounted, as shown in FIGS. 1-3, andis configured to support an attached body 85, as shown in FIG. 4. Aperson of ordinary skill in the art will recognize that the structuralframe 11 can take many different forms, in addition to the cage-likestructure of the embodiment depicted in FIGS. 1-3. For example, thestructural frame 11 can be a traditional automotive frame having two ormore longitudinal structural members spaced a distance apart from eachother, with two or more transverse structural members spaced apart fromeach other and attached to both longitudinal structural members at theirends. Alternatively, the structural frame may also be in the form of a“belly pan,” wherein integrated rails and cross members are formed insheets of metal or other suitable material, with other formations toaccommodate various system components. The structural frame may also beintegrated with various chassis components.

Referring to FIG. 2, a body attachment interface 87 is defined as thesum of all body connection components, i.e., connective elements thatfunction to operably mate a vehicle body to the chassis 10. The bodyconnection components of the preferred embodiment include a plurality ofload-bearing body-retention couplings 89 mounted with respect to thestructural frame 11 and a single electrical connector 91.

As shown in FIG. 4, the load-bearing body-retention couplings 89 areengageable with complementary attachment couplings 93 on a vehicle body85 and function to physically fasten the vehicle body 85 to the chassis10. Those skilled in the art will recognize that a multitude offastening and locking elements may be used and fall within the scope ofthe claimed invention. The load-bearing body-retention couplings 89 arepreferably releasably engageable with complementary couplings, thoughnon-releasably engageable couplings such as weld flanges or rivetingsurfaces may be employed within the scope of the claimed invention.Ancillary fastening elements may be used as lock downs in conjunctionwith the load-bearing body-retention couplings. Load-bearing surfaceswithout locking or fastening features on the chassis 10 may be used withthe load-bearing body-retention couplings 89 to support the weight of anattached vehicle body 85. In the preferred embodiment, the load-bearingbody-retention couplings 89 include support brackets with bolt holes.Rubber mounts (not shown) located on the support brackets dampenvibrations transmitted between the body and the chassis. Alternatively,hard mounts may be employed for body-retention couplings.

The electrical connector 91 is engageable with a complementaryelectrical connector 95 on a vehicle body 85. The electrical connector91 of the preferred embodiment may perform multiple functions, or selectcombinations thereof. First, the electrical connector 91 may function asan electrical power connector, i.e., it may be configured to transferelectrical energy generated by components on the chassis 10 to a vehiclebody 85 or other non-chassis destination. Second, the electricalconnector 91 may function as a control signal receiver, i.e., a deviceconfigured to transfer non-mechanical control signals from a non-chassissource to controlled systems including the energy conversion system,steering system, and braking system. Third, the electrical connector 91may function as a feedback signal conduit through which feedback signalsare made available to a vehicle driver. Fourth, the electrical connector91 may function as an external programming interface through whichsoftware containing algorithms and data may be transmitted for use bycontrolled systems. Fifth, the electrical connector may function as aninformation conduit through which sensor information and otherinformation is made available to a vehicle driver. The electricalconnector 91 may thus function as a communications and power “umbilical”port through which all communications between the chassis 10 and anattached vehicle body 85 are transmitted. Electrical connectors includedevices configured to operably connect one or more electrical wires withother electrical wires. The wires may be spaced a distance apart toavoid any one wire causing signal interference in another wire operablyconnected to an electrical connector or for any reason that wires inclose proximity may not be desirable.

If one electrical connector performing multiple functions is notdesirable, for example, if a cumbersome wire bundle is required, orpower transmission results in control signal interference, the bodyattachment interface 87 may include a plurality of electrical connectors91 engageable with a plurality of complementary electrical connectors 95on a vehicle body 85, with different connectors performing differentfunctions. A complementary electrical connector 95 performs functionscomplementary to the function of the electrical connector with which itengages, for example, functioning as a control signal transmitter whenengaged with a control signal receiver.

Referring again to FIGS. 1-3, the energy conversion system 67, energystorage system 69, steering system 81, and braking system 83, areconfigured and positioned on the chassis 10 to minimize the overallvertical height of the chassis 10 and to maintain a substantiallyhorizontal upper chassis face 96. A face of an object is an imaginarysurface that follows the contours of the object that face, and aredirectly exposed to, a particular direction. Thus, the upper chassisface 96 is an imaginary surface that follows the upwardly facing andexposed contours of the chassis frame 11 and systems mounted therein.Matable vehicle bodies have a corresponding lower body face 97 that isan imaginary surface that follows the downwardly facing and exposedcontours of the body 85, as shown in FIG. 4.

Referring again to FIGS. 1-3, the structural frame 11 has a thicknessdefined as the vertical distance between its highest point (the top ofstructural element 20) and its lowest point (the bottom of structuralelement 22). In the preferred embodiment, the structural frame thicknessis approximately 11 inches. To achieve a substantially horizontal upperchassis face 96, the energy conversion system 67, energy storage system69, steering system 81, and braking system 83 are distributed throughoutthe open spaces and are configured, positioned, and mounted to thestructural frame 11 such that the highest point of any of the energyconversion system 67, energy storage system 69, steering system 81, andbraking system 83 does not extend or protrude higher than the highestpoint of the structural frame 11 by an amount more than 50% of thestructural frame thickness. Alternatively, the highest point of any ofthe energy conversion system 67, energy storage system 69, steeringsystem 81, and braking system 83 does not extend or protrude higher thanthe top of any of the tires 80. Alternatively, the highest point of anyof the energy conversion system 67, energy storage system 69, steeringsystem 81, and braking system 83 does not extend or protrude higher thanthe top of any of the wheels 73, 75, 77, 79. In the context of thepresent invention, a tire is not considered part of a wheel. A wheeltypically comprises a rim and a wheel disc or nave that connects the rimto a wheel hub, and does not include a mounted tire. A tire is mountedaround the periphery of a wheel. The substantially horizontal upperchassis face 96 enables the attached vehicle body 85 to have a passengerarea that extends the length of the chassis, unlike prior art bodiesthat have an engine compartment to accommodate a vertically-protrudinginternal combustion engine.

Most of the powertrain load is evenly distributed between the front andrear of the chassis so there is a lower center of gravity for the wholevehicle without sacrificing ground clearance, thereby enabling improvedhandling while resisting rollover forces.

Referring again to FIG. 4, the preferred embodiment of the rollingplatform 10 is configured such that the lower body face 97 of a matablevehicle body 85 is positioned closely adjacent to the upper chassis face96 for engagement with the rolling platform 10. The body connectioncomponents have a predetermined spatial relationship relative to oneanother, and are sufficiently positioned, exposed, and unobstructed suchthat when a vehicle body 85 having complementary connection components(complementary attachment couplings 93 and a complementary electricalconnector 95) in the same predetermined spatial relationship as the bodyconnection components is sufficiently positioned relative to the upperchassis face 96 of a chassis 10 of the invention, the complementaryconnection components are adjacent to corresponding body connectioncomponents and ready for engagement, as depicted in FIG. 4. In thecontext of the present invention, a body connection component having aprotective covering is exposed and unobstructed if the protectivecovering is removable or retractable.

Each body connection component has a spatial relationship relative toeach of the other body connection components that can be expressed, forexample, as a vector quantity. Body connection components andcomplementary connection components have the same predetermined spatialrelationship if the vector quantities that describe the spatialrelationship between a body connection component and the other bodyconnection components to be engaged also describe the spatialrelationship between a corresponding complementary connection componentand the other complementary connection components to be engaged. Forexample, the spatial relationship may be defined as follows: a firstbody connection component is spaced a distance Ax+By from a referencepoint; a second body connection component is spaced a distance Cx+Dyfrom the reference point; a third body connection component is spaced adistance Ex+Fy from the reference point, etc. Correspondingcomplementary connection components in the same predetermined spatialrelationship are spaced in a mirror image relationship in the lower bodyface, as depicted in FIGS. 4 and 5. A protective covering (not shown)may be employed to protect any of the body connection components.

The body connection components and the complementary connectioncomponents are preferably adjacent without positional modification whena vehicle body 85 is sufficiently positioned relative to a chassis 10 ofthe invention; however, in the context of the present invention, thebody connection components may be movable relative to each other withina predetermined spatial relationship to accommodate build tolerances orother assembly issues. For example, an electrical connector may bepositioned and operably connected to a signal-carrying cable. The cablemay be fixed relative to the structural frame at a point six inches fromthe electrical connector. The electrical connector will thus be movablewithin six inches of the fixed point on the cable. A body connectioncomponent is considered adjacent to a complementary connection componentif one or both are movable within a predetermined spatial relationshipso as to be in contact with each other.

Referring to FIG. 5, the body-attachment interface of the claimedinvention enables compatibility between the chassis 10 and differenttypes of bodies 85, 85′, 85″ having substantially different designs.Bodies 85, 85′, 85″ having a common base 98 with complementaryattachment couplings 93 and complementary electrical connectors 95 inthe same predetermined spatial relationship with one another as thepredetermined spatial relationship between body connection components onthe body-attachment interface 87, are each matable with the chassis 10by positioning the body 85, 85′, 85″ relative to the chassis 10 suchthat each complementary attachment coupling 93 is adjacent to aload-bearing body-retention coupling 89, and the complementaryelectrical connector 95 is adjacent to the electrical connector 91.Preferably, all bodies and chassis comply with this common, standardizedinterface system, thereby facilitating compatibility between a widearray of different body types and styles and a single chassis design.The substantially horizontal upper chassis face 96 also facilitatescompatibility between the rolling platform 10 and a multitude ofdifferently-configured body styles. The common base 98 functions as abody structural unit and forms the lower body face 97 in the embodimentdepicted. FIG. 5 schematically depicts a sedan 85, a van 85′, and apickup truck 85″ each having a common base 98.

The body connection components are preferably sufficiently exposed at achassis face to facilitate attachment to complementary connectioncomponents on a matable vehicle body. Similarly, complementaryconnection components on a matable vehicle body are sufficiently exposedat a body face to facilitate attachment to body connection components ona vehicle chassis. The body connection components are preferably locatedat or above the upper chassis face for engagement with complementaryconnection components located at or below a lower body face.

A connection device may be employed to engage or operably connect a bodyconnection component with a distant complementary connection component,in the situation where a vehicle body does not have complementaryconnection components in the same predetermined spatial relationship asthe body connection components on a vehicle chassis. For example, acable having two connectors, one connector engageable with theelectrical connector on a body attachment interface and the otherconnector engageable with a complementary connector on a matable vehiclebody, may be used to operably connect the electrical connector and thecomplementary connector.

The bodies 85, 85′, 85″ shown schematically in FIG. 5 each use all ofthe body connection components on the vehicle chassis 10. However,within the scope of the claimed invention, a chassis may have more bodyconnection components than are actually mated with a vehicle body. Forexample, a chassis may have ten load-bearing body-retention couplings,and be matable with a body that engages only five of the tenload-bearing body-retention couplings. Such an arrangement isparticularly useful when an attachable body is of a different size thanthe chassis. For example, a matable body may be smaller than a chassis.Similarly, and within the scope of the claimed invention, a body may bemodular such that separate body components are independently connectedto the vehicle chassis by the load-bearing body-retention couplings.

A body may have more complementary connection components than areengageable with the body connection components of a particular chassis.Such an arrangement may be employed to enable a particular body to bematable to multiple chassis each having a different predeterminedspatial relationship among its body connection components.

The load-bearing body-retention couplings 89 and the electricalconnector 91 are preferably releasably engageable without damage toeither an attached body 85 or the chassis 10, thereby enabling removalof one body 85 from the chassis 10 and installation of a different body85′, 85″ on the chassis 10.

In the preferred embodiment, the body-attachment interface 87 ischaracterized by the absence of any mechanical controlsignal-transmission linkages and any couplings for attaching mechanicalcontrol signal-transmission linkages. Mechanical control linkages, suchas steering columns, limit the compatibility between a chassis andbodies of different configurations.

Referring to FIG. 1, the steering system 81 is housed in the front axlearea 16 and is operably connected to the front wheels 73, 75.Preferably, the steering system 81 is responsive to non-mechanicalcontrol signals. In the preferred embodiment, the steering system 81 isby-wire. A by-wire system is characterized by control signaltransmission in electrical form. In the context of the presentinvention, “by-wire” systems, or systems that are controllable“by-wire,” include systems configured to receive control signals inelectronic form via a control signal receiver on the body attachmentinterface 87, and respond in conformity to the electronic controlsignals.

Referring to FIG. 6, the by-wire steering system 81 of the preferredembodiment includes a steering control unit 99, and a steering actuator100. Sensors 101 are located on the chassis 10 and transmit sensorsignals 102 carrying information concerning the state or condition ofthe chassis 10 and its component systems. The sensors 101 may includeposition sensors, velocity sensors, acceleration sensors, pressuresensors, force and torque sensors, flow meters, temperature sensors,etc. The steering control unit 99 receives and processes sensor signals102 from the sensors 101 and electrical steering control signals 103from the electrical connector 91, and generates steering actuatorcontrol signals 104 according to a stored algorithm. A control unittypically includes a microprocessor, ROM and RAM and appropriate inputand output circuits of a known type for receiving the various inputsignals and for outputting the various control commands to theactuators. Sensor signals 102 may include yaw rate, lateralacceleration, angular wheel velocity, tie-rod force, steering angle,chassis velocity, etc.

The steering actuator 100 is operably connected to the front wheels 73,75 and configured to adjust the steering angle of the front wheels 73,75 in response to the steering actuator control signals 104. Actuatorsin a by-wire system transform electronic control signals into amechanical action or otherwise influence a system's behavior in responseto the electronic control signals. Examples of actuators that may beused in a by-wire system include electromechanical actuators such aselectric servomotors, translational and rotational solenoids,magnetorheological actuators, electrohydraulic actuators, andelectrorheological actuators. Those skilled in the art will recognizeand understand mechanisms by which the steering angle is adjusted. Inthe preferred embodiment, the steering actuator 100 is an electric drivemotor configured to adjust a mechanical steering rack.

Referring again to FIG. 6, the preferred embodiment of the chassis 10 isconfigured such that it is steerable by any source of compatibleelectrical steering control signals 103 connected to the electricalconnector 91. FIG. 6 depicts a steering transducer 105 located on anattached vehicle body 85 and connected to a complementary electricalconnector 95. Transducers convert the mechanical control signals of avehicle driver to non-mechanical control signals. When used with aby-wire system, transducers convert the mechanical control signals toelectrical control signals usable by the by-wire system. A vehicledriver inputs control signals in mechanical form by turning a wheel,depressing a pedal, pressing a button, or the like. Transducers utilizesensors, typically position and force sensors, to convert the mechanicalinput to an electrical signal. In the preferred embodiment, a +/−20degree slide mechanism is used for driver input, and an optical encoderis used to read input rotation.

The complementary electrical connector 95 is coupled with the electricalconnector 91 of the body attachment interface 87. The steeringtransducer 105 converts vehicle driver-initiated mechanical steeringcontrol signals 106 to electrical steering control signals 103 which aretransmitted via the electrical connector 91 to the steering control unit99. In the preferred embodiment, the steering control unit 99 generatessteering feedback signals 107 for use by a vehicle driver and transmitsthe steering feedback signals 107 through the electrical connector 91.Some of the sensors 101 monitor linear distance movement of the steeringrack and vehicle speed. This information is processed by the steeringcontrol unit 99 according to a stored algorithm to generate the steeringfeedback signals 107. A torque control motor operably connected to theslide mechanism receives the steering feedback signals 107 and is drivenin the opposite direction of the driver's mechanical input.

In the context of the present invention, a “by-wire” system may be anactuator connected directly to an electrical connector in the bodyattachment interface. An alternative by-wire steering system 81′ withinthe scope of the claimed invention is depicted schematically in FIG. 7,wherein like reference numbers refer to like components from FIG. 6. Asteering actuator 100 configured to adjust the steering angle of thefront wheels 73, 75 is connected directly to the electrical connector91. In this embodiment, a steering control unit 99′ and a steeringtransducer 105 may be located in an attached vehicle body 85. Thesteering transducer 105 would transmit electrical steering controlsignals 103 to the steering control unit 99′, and the steering controlunit 99′ would transmit steering actuator control signals 104 to thesteering actuator 100 via the electrical connector 91. Sensors 101positioned on the chassis 10 transmit sensor signals 102 to the steeringcontrol unit 99′ via the electrical connector 91 and the complementaryelectrical connector 95.

Examples of steer-by-wire systems are described in U.S. Pat. Nos.6,176,341, issued Jan. 23, 2001 to Ansari; 6,208,923, issued Mar. 27,2001 to Hommel; 6,219,604, issued Apr. 17, 2001 to Dilger, et al.;6,318,494, issued Nov. 20, 2001 to Pattok; 6,370,460, issued Apr. 9,2002 to Kaufmann, et al.; and 6,394,218, issued May 28, 2002 to Heitzer;which are hereby incorporated by reference in their entireties.

The steer-by-wire system described in U.S. Pat. No. 6,176,341 includes aposition sensor for sensing angular position of a road wheel, ahand-operated steering wheel for controlling direction of the roadwheel, a steering wheel sensor for sensing position of the steeringwheel, a steering wheel actuator for actuating the hand-operatedsteering wheel, and a steering control unit for receiving the sensedsteering wheel position and the sensed road wheel position andcalculating actuator control signals, preferably including a road wheelactuator control signal and a steering wheel actuator control signal, asa function of the difference between the sensed road wheel position andthe steering wheel position. The steering control unit commands the roadwheel actuator to provide controlled steering of the road wheel inresponse to the road wheel actuator control signal. The steering controlunit further commands the steering wheel actuator to provide feedbackforce actuation to the hand-operated steering wheel in response to thesteering wheel control signal. The road wheel actuator control signaland steering wheel actuator control signal are preferably scaled tocompensate for difference in gear ratio between the steering wheel andthe road wheel. In addition, the road wheel actuator control signal andsteering wheel actuator control signal may each have a gain set so thatthe road wheel control actuator signal commands greater force actuationto the road wheel than the feedback force applied to the steering wheel.

The steer-by-wire system described in U.S. Pat. No. 6,176,341 preferablyimplements two position control loops, one for the road wheel and onefor the hand wheel. The position feedback from the steering wheelbecomes a position command input for the road wheel control loop and theposition feedback from the road wheel becomes a position command inputfor the steering wheel control loop. A road wheel error signal iscalculated as the difference between the road wheel command input(steering wheel position feedback) and the road wheel position.Actuation of the road wheel is commanded in response to the road wheelerror signal to provide controlled steering of the road wheel. Asteering wheel error signal is calculated as the difference between thesteering wheel position command (road wheel position feedback) and thesteering wheel position. The hand-operated steering wheel is actuated inresponse to the steering wheel error signal to provide force feedback tothe hand-operated steering wheel.

The steering control unit of the '341 system could be configured as asingle processor or multiple processors and may include ageneral-purpose microprocessor-based controller, that may include acommercially available off-the-shelf controller. One example of acontroller is Model No. 87C196CA microcontroller manufactured and madeavailable from Intel Corporation of Delaware. The steering control unitpreferably includes a processor and memory for storing and processingsoftware algorithms, has a clock speed of 16 MHz, two optical encoderinterfaces to read position feedbacks from each of the actuator motors,a pulse width modulation output for each motor driver, and a 5-voltregulator.

U.S. Pat. No. 6,370,460 describes a steer-by-wire control systemcomprising a road wheel unit and a steering wheel unit that operatetogether to provide steering control for the vehicle operator. Asteering control unit may be employed to support performing the desiredsignal processing. Signals from sensors in the road wheel unit, steeringwheel unit, and vehicle speed are used to calculate road wheel actuatorcontrol signals to control the direction of the vehicle and steeringwheel torque commands to provide tactile feedback to the vehicleoperator. An Ackerman correction may be employed to adjust the left andright road wheel angles correcting for errors in the steering geometryto ensure that the wheels will track about a common turn center.

Referring again to FIG. 1, a braking system 83 is mounted to thestructural frame 11 and is operably connected to the wheels 73, 75, 77,79. The braking system is configured to be responsive to non-mechanicalcontrol signals. In the preferred embodiment, the braking system 83 isby-wire, as depicted schematically in FIG. 8, wherein like referencenumbers refer to like components from FIGS. 6 and 7. Sensors 101transmit sensor signals 102 carrying information concerning the state orcondition of the chassis 10 and its component systems to a brakingcontrol unit 108. The braking control unit 108 is connected to theelectrical connector 91 and is configured to receive electrical brakingcontrol signals 109 via the electrical connector 91. The braking controlunit 108 processes the sensor signals 102 and the electrical brakingcontrol signals 109 and generates braking actuator control signals 110according to a stored algorithm. The braking control unit 108 thentransmits the braking actuator control signals 110 to braking actuators111, 112, 113, 114 which act to reduce the angular velocity of thewheels 73, 75, 77, 79. Those skilled in the art will recognize themanner in which the braking actuators 111, 112, 113, 114 act on thewheels 73, 75, 77, 79. Typically, actuators cause contact betweenfriction elements, such as pads and disc rotors. Optionally, an electricmotor may function as a braking actuator in a regenerative brakingsystem.

The braking control unit 108 may also generate braking feedback signals115 for use by a vehicle driver and transmit the braking feedbacksignals 115 through the electrical connector 91. In the preferredembodiment, the braking actuators 111, 112, 113, 114 apply force througha caliper to a rotor at each wheel. Some of the sensors 101 measure theapplied force on each caliper. The braking control unit 108 uses thisinformation to ensure synchronous force application to each rotor.

Referring again to FIG. 8, the preferred embodiment of the chassis 10 isconfigured such that the braking system is responsive to any source ofcompatible electrical braking control signals 109. A braking transducer116 may be located on an attached vehicle body 85 and connected to acomplementary electrical connector 95 coupled with the electricalconnector 91. The braking transducer 116 converts vehicledriver-initiated mechanical braking control signals 117 into electricalform and transmits the electrical braking control signals 109 to thebraking control unit via the electrical connector 91. In the preferredembodiment, the braking transducer 116 includes two hand-grip typeassemblies. The braking transducer 116 includes sensors that measureboth the rate of applied pressure and the amount of applied pressure tothe hand-grip assemblies, thereby converting mechanical braking controlsignals 117 to electrical braking control signals 109. The brakingcontrol unit 108 processes both the rate and amount of applied pressureto provide both normal and panic stopping.

An alternative brake-by-wire system 83′ within the scope of the claimedinvention is depicted in FIG. 9, wherein like reference numbers refer tolike components from FIGS. 6-8. The braking actuators 111, 112, 113, 114and sensors 101 are connected directly to the electrical connector 91.In this embodiment, a braking control unit 108′ may be located in anattached vehicle body 85. A braking transducer 116 transmits electricalbraking control signals 109 to the braking control unit 108′, and thebraking control unit 108′ transmits braking actuator signals 109 to thebraking actuators 111, 112, 113, 114 via the electrical connector 91.

Examples of brake-by-wire systems are described in U.S. Pat. Nos.5,366,281, issued Nov. 22, 2994 to Littlejohn; 5,823,636, issued Oct.20, 1998 to Parker, et al.; 6,305,758, issued Oct. 23, 2001 to Hageman;and 6,390,565, issued May 21, 2002 to Riddiford, et al.; which arehereby incorporated by reference in their entireties.

The system described in U.S. Pat. No. 5,366,281 includes an input devicefor receiving mechanical braking control signals, a brake actuator and acontrol unit coupled to the input device and the brake actuator. Thecontrol unit receives brake commands, or electrical braking controlsignals, from the input device and provides actuator commands, orbraking actuator control signals, to control current and voltage to thebrake actuator. When a brake command is first received from the inputdevice, the control unit outputs, for a first predetermined time period,a brake torque command to the brake actuator commanding maximum currentto the actuator. After the first predetermined time period, the controlunit outputs, for a second predetermined time period, a brake torquecommand to the brake actuator commanding voltage to the actuatorresponsive to the brake command and a first gain factor. After thesecond predetermined time period, the control unit outputs the braketorque command to the brake actuator commanding current to the actuatorresponsive to the brake command and a second gain factor, wherein thefirst gain factor is greater than the second gain factor and whereinbrake initialization is responsive to the brake input.

U.S. Pat. No. 6,390,565 describes a brake-by-wire system that providesthe capability of both travel and force sensors in a braking transducerconnected to a brake apply input member such as a brake pedal and alsoprovides redundancy in sensors by providing the signal from a sensorresponsive to travel or position of the brake apply input member to afirst control unit and the signal from a sensor responsive to forceapplied to a brake apply input member to a second control unit. Thefirst and second control units are connected by a bi-directionalcommunication link whereby each controller may communicate its receivedone of the sensor signals to the other control unit. In at least one ofthe control units, linearized versions of the signals are combined forthe generation of first and second brake apply command signals forcommunication to braking actuators. If either control unit does notreceive one of the sensor signals from the other, it neverthelessgenerates its braking actuator control signal on the basis of the sensorsignal provided directly to it. In a preferred embodiment of the system,a control unit combines the linearized signals by choosing the largestin magnitude.

Referring again to FIG. 1, the energy storage system 69 stores energythat is used to propel the chassis 10. For most applications, the storedenergy will be in chemical form. Examples of energy storage systems 69include fuel tanks and electric batteries. In the embodiment shown inFIG. 1, the energy storage system 69 includes two compressed gascylinder storage tanks 121 (5,000 psi, or 350 bars) mounted within themid-chassis space 41 and configured to store compressed hydrogen gas.Employing more than two compressed gas cylinder storage tanks may bedesirable to provide greater hydrogen storage capacity. Instead ofcompressed gas cylinder storage tanks 121, an alternate form of hydrogenstorage may be employed such as metal or chemical hydrides. Hydrogengeneration or reforming may also be used.

The energy conversion system 67 converts the energy stored by the energystorage system 69 to mechanical energy that propels the chassis 10. Inthe preferred embodiment, depicted in FIG. 1, the energy conversionsystem 67 includes a fuel cell stack 125 located in the rear axle area18, and an electric traction motor 127 located in the front axle area16. The fuel cell stack 125 produces a continuously available power of94 kilowatts. Fuel cell systems for vehicular use are described in U.S.Pat. Nos. 6,195,999, issued Mar. 6, 2001 to Arnold, et al.; 6,223,843,issued May 1, 2001 to O'Connell, et al.; 6,321,145, issued Nov. 20, 2001to Rajashekara; and 6,394,207, issued May 28, 2002 to Skala; which arehereby incorporated by reference in their entireties.

The fuel cell stack 125 is operably connected to the compressed gascylinder storage tanks 121 and to the traction motor 127. The fuel cellstack 125 converts chemical energy in the form of hydrogen from thecompressed gas cylinder storage tanks 121 into electrical energy, andthe traction motor 127 converts the electrical energy to mechanicalenergy, and applies the mechanical energy to rotate the front wheels 73,75. Optionally, the fuel cell stack 125 and traction motor 127 areswitched between the front axle area 16 and rear axle area 18.Optionally, the energy conversion system includes an electric battery(not shown) in hybrid combination with the fuel cell to improve chassisacceleration. Other areas provided between the structural elements areuseful for housing other mechanisms and systems for providing thefunctions typical of an automobile as shown in FIGS. 2 and 3. Thoseskilled in the art will recognize other energy conversion systems 67that may be employed within the scope of the present invention.

The energy conversion system 67 is configured to respond tonon-mechanical control signals. The energy conversion system 67 of thepreferred embodiment is controllable by-wire, as depicted in FIG. 10. Anenergy conversion system control unit 128 is connected to the electricalconnector 91 from which it receives electrical energy conversion systemcontrol signals 129, and sensors 101 from which it receives sensorsignals 102 carrying information about various chassis conditions. Inthe preferred embodiment, the information conveyed by the sensor signals102 to the energy conversion system control unit 128 includes chassisvelocity, electrical current applied, rate of acceleration of thechassis, and motor shaft speed to ensure smooth launches and controlledacceleration. The energy conversion system control unit 128 is connectedto an energy conversion system actuator 130, and transmits energyconversion system actuator control signals 131 to the energy conversionsystem actuator 130 in response to the electrical energy conversionsystem control signals 129 and sensor signals 102 according to a storedalgorithm. The energy conversion system actuator 130 acts on the fuelcell stack 125 or traction motor 127 to adjust energy output. Thoseskilled in the art will recognize the various methods by which theenergy conversion system actuator 130 may adjust the energy output ofthe energy conversion system. For example, a solenoid may alternatelyopen and close a valve that regulates hydrogen flow to the fuel cellstack. Similarly, a compressor that supplies oxygen (from air) to thefuel cell stack may function as an actuator, varying the amount ofoxygen supplied to the fuel cell stack in response to signals from theenergy conversion system control unit.

An energy conversion system transducer 132 may be located on a vehiclebody 85 and connected to a complementary electrical connector 95 engagedwith the electrical connector 91. The energy conversion systemtransducer 132 is configured to convert mechanical energy conversionsystem control signals 133 to electrical energy conversion systemcontrol signals 129.

In another embodiment of the invention, as shown schematically in FIG.11, wherein like reference numbers refer to like components from FIGS.6-10, wheel motors 135, also known as wheel hub motors, are positionedat each of the four wheels 73, 75, 77, 79. Optionally, wheel motors 135may be provided at only the front wheels 73, 75 or only the rear wheels77, 79. The use of wheel motors 135 reduces the height of the chassis 10compared to the use of traction motors, and therefore may be desirablefor certain uses.

Referring again to FIG. 2, a conventional heat exchanger 137 andelectric fan system 139, operably connected to the fuel cell stack 125to circulate coolant for waste heat rejection, is carried in an openingthat exists between the rear axle area 18 and the structural elements54, 60. The heat exchanger 137 is set at an inclined angle to reduce itsvertical profile, but to provide adequate heat rejection it also extendsslightly above the top of elements 12, 26 (as seen in FIG. 4). Althoughthe fuel cell stack 125, heat exchanger 137 and electric fan system 139extend above the structural elements, their protrusion into the body podspace is relatively minor when compared to the engine compartmentrequirements of a conventionally designed automobile, especially whenthe chassis height of the preferred embodiment is approximately a mere15 inches (28 centimeters). Optionally, the heat exchanger 137 ispackaged completely within the chassis' structure with airflow routedthrough channels (not shown).

Referring again to FIG. 1, the suspension system 71 is mounted to thestructural frame 11 and is connected to four wheels 73, 75, 77, 79.Those skilled in the art will understand the operation of a suspensionsystem, and recognize that a multitude of suspension system types may beused within the scope of the claimed invention. The suspension system 71of the preferred embodiment of the invention is electronicallycontrolled, as depicted schematically in FIG. 12.

Referring to FIG. 12, the behavior of the electronically controlledsuspension system 71 in response to any given road input is determinedby a suspension control unit 141. Sensors 101 located on the chassis 10monitor various conditions such as vehicle speed, angular wheelvelocity, and wheel position relative to the chassis 10. The sensors 101transmit the sensor signals 102 to the suspension control unit 141. Thesuspension control unit 141 processes the sensor signals 102 andgenerates suspension actuator control signals 142 according to a storedalgorithm. The suspension control unit 141 transmits the suspensionactuator control signals 142 to four suspension actuators 143, 144, 145,146. Each suspension actuator 143, 144, 145, 146 is operably connectedto a wheel 73, 75, 77, 79 and determines, in whole or in part, theposition of the wheel 73, 75, 77, 79 relative to the chassis 10. Thesuspension actuators of the preferred embodiment are variable-force,real time, controllable dampers. The suspension system 71 of thepreferred embodiment is also configured such that chassis ride height isadjustable. Separate actuators may be used to vary the chassis rideheight.

In the preferred embodiment, the suspension control unit 141 isprogrammable and connected to the electrical connector 91 of thebody-attachment interface 87. A vehicle user is thus able to altersuspension system 71 characteristics by reprogramming the suspensioncontrol unit 141 with suspension system software 147 via the electricalconnector 91.

In the context of the claimed invention, electronically-controlledsuspension systems include suspension systems without a suspensioncontrol unit located on the chassis 10. Referring to FIG. 13, whereinlike reference numbers are used to reference like components from FIG.12, suspension actuators 143, 144, 145, 146 and suspension sensors 101are connected directly to the electrical connector 91. In such anembodiment, a suspension control unit 141′ located on an attachedvehicle body 85 can process sensor signals 102 transmitted through theelectrical connector 91, and transmit suspension actuator controlsignals 142 to the suspension actuators 143, 144, 145, 146 via theelectrical connector 91.

Examples of electronically controlled suspension systems are describedin U.S. Pat. Nos. 5,606,503, issued Feb. 25, 1997 to Shal, et al.;5,609,353, issued Mar. 11, 1997 to Watson; and 6,397,134, issued May 28,2002 to Shal, et al.; which are hereby incorporated by reference intheir entireties.

U.S. Pat. No. 6,397,134 describes an electronically controlledsuspension system that provides improved suspension control throughsteering crossover events. In particular, the system senses a vehiclelateral acceleration and a vehicle steering angle and stores, for eachdirection of sensed vehicle lateral acceleration, first and second setsof enhanced suspension actuator control signals for the suspensionactuators of the vehicle. Responsive to the sensed vehicle lateralacceleration and sensed vehicle steering angle, the system applies thefirst set of enhanced actuator control signals to the suspensionactuators if the sensed steering angle is in the same direction as thesensed lateral acceleration and alternatively applies the second set ofenhanced actuator control signals to the suspension actuators if thesensed steering angle is in the opposite direction as the sensed lateralacceleration.

U.S. Pat. No. 5,606,503 describes a suspension control system for use ina vehicle including a suspended vehicle body, four un-suspended vehiclewheels, four variable force actuators mounted between the vehicle bodyand wheels, one of the variable force actuators at each corner of thevehicle, and a set of sensors providing sensor signals indicative ofmotion of the vehicle body, motion of the vehicle wheels, a vehiclespeed and an ambient temperature. The suspension control systemcomprises a microcomputer control unit including: means for receivingthe sensor signals; means, responsive to the sensor signals, fordetermining an actuator demand force for each actuator; means,responsive to the vehicle speed, for determining a first signalindicative of a first command maximum; means, responsive to the ambienttemperature, for determining a second signal indicative of a secondcommand maximum; and means for constraining the actuator demand force sothat it is no greater than a lesser of the first and second commandmaximums.

Electrically conductive wires (not shown) are used in the preferredembodiment to transfer signals between the chassis 10 and an attachedbody 85, and between transducers, control units, and actuators. Thoseskilled in the art will recognize that other non-mechanical means ofsending and receiving signals between a body and a chassis, and betweentransducers, control units, and actuators may be employed and fallwithin the scope of the claimed invention. Other non-mechanical means ofsending and receiving signals include radio waves and fiber optics.

The by-wire systems are networked in the preferred embodiment, in partto reduce the quantity of dedicated wires connected to the electricalconnector 91. A serial communication network is described in U.S. Pat.No. 5,534,848, issued Jul. 9, 1996 to Steele, et al., which is herebyincorporated by reference in its entirety. An example of a networkeddrive-by-wire system is described in U.S. Patent Application PublicationNo. US 2001/0029408, Ser. No. 09/775,143, which is hereby incorporatedby reference in its entirety. Those skilled in the art will recognizevarious networking devices and protocols that may be used within thescope of the claimed invention, such as SAE J1850 and CAN (“ControllerArea Network”). A TTP (“Time Triggered Protocol”) network is employed inthe preferred embodiment of the invention for communications management.

Some of the information collected by the sensors 101, such as chassisvelocity, fuel level, and system temperature and pressure, is useful toa vehicle driver for operating the chassis and detecting systemmalfunctions. As shown in FIG. 14, the sensors 101 are connected to theelectrical connector 91 through a chassis computer 153. Sensor signals102 carrying information are transmitted from the sensors 101 to thechassis computer 153, which processes the sensor signals 102 accordingto a stored algorithm. The chassis computer 153 transmits the sensorsignals 102 to the electrical connector 91 when, according to the storedalgorithm, the sensor information is useful to the vehicle driver. Forexample, a sensor signal 102 carrying temperature information istransmitted to the electrical connector 91 by the chassis computer 153when the operating temperature of the chassis 10 is unacceptably high. Adriver-readable information interface 155 may be attached to acomplementary electrical connector 95 coupled with the electricalconnector 91 and display the information contained in the sensor signals102. Driver-readable information interfaces include, but are not limitedto, gauges, meters, LED displays, and LCD displays. The chassis may alsocontain communications systems, such as antennas and telematics systems,that are operably connected to an electrical connector in thebody-attachment interface and configured to transmit information to anattached vehicle body.

One control unit may serve multiple functions. For example, as shown inFIG. 15, a master control unit 159 functions as the steering controlunit, braking control unit, suspension control unit, and energyconversion system control unit.

Referring again to FIG. 15, the energy conversion system 67 isconfigured to transmit electrical energy 160 to the electrical connector91 to provide electric power for systems located on an attached vehiclebody, such as power windows, power locks, entertainment systems,heating, ventilating, and air conditioning systems, etc. Optionally, ifthe energy storage system 69 includes a battery, then the battery may beconnected to the electrical connector 91. In the preferred embodiment,the energy conversion system 67 includes a fuel cell stack thatgenerates electrical energy and is connected to the electrical connector91.

FIG. 16 shows a chassis 10 with rigid covering, or “skin,” 161 and anelectrical connector or coupling 91 that functions as an umbilical port.The rigid covering 161 may be configured to function as a vehicle floor,which is useful if an attached vehicle body 85 does not have a lowersurface. In FIG. 17, a similarly equipped chassis 10 is shown with anoptional vertical fuel cell stack 125. The vertical fuel cell stack 125protrudes significantly into the body pod space which is acceptable forsome applications. The chassis 10 also includes a manual parking brakeinterface 162 that may be necessary for certain applications andtherefore is also optionally used with other embodiments.

FIG. 18 depicts an embodiment of the invention that may be advantageousin some circumstances. The energy conversion system 67 includes aninternal combustion engine 167 with horizontally-opposed cylinders, anda transmission 169. The energy storage system 69 includes a gasolinetank 171.

FIG. 19 depicts an embodiment of the invention wherein the steeringsystem 81 has mechanical control linkages including a steering column173. Passenger seating attachment couplings 175 are present on the bodyattachment interface 87, allowing the attachment of passenger seatingassemblies to the chassis 10.

FIGS. 20 and 20 a depict a chassis 10 within the scope of the inventionand a body 85 each having multiple electrical connectors 91 and multiplecomplementary electrical connectors 95, respectively. For example, afirst electrical connector 91 may be operably connected to the steeringsystem and function as a control signal receiver. A second electricalconnector 91 may be operably connected to the braking system andfunction as a control signal receiver. A third electrical connector 91may be operably connected to the energy conversion system and functionas a control signal receiver. A fourth electrical connector 91 may beoperably connected to the energy conversion system and function as anelectrical power connector. Four multiple wire in-line connectors andcomplementary connectors are used in the embodiment shown in FIGS. 20and 20 a. FIG. 20 a depicts an assembly process for attachingcorresponding connectors 91, 95.

Referring to FIG. 21, a further embodiment of the claimed invention isdepicted. The chassis 10 has a rigid covering 161 and a plurality ofpassenger seating attachment couplings 175. A driver-operable controlinput device 177 containing a steering transducer, a braking transducer,and an energy conversion system transducer, is operably connected to thesteering system, braking system, and energy conversion system by wires179 and movable to different attachment points.

The embodiment depicted in FIG. 21 enables bodies of varying designs andconfigurations to mate with a common chassis design. A vehicle bodywithout a lower surface but having complementary attachment couplings ismatable to the chassis 10 at the load-bearing body retention couplings89. Passenger seating assemblies may be attached at passenger seatingattachment couplings 175.

Referring to FIG. 22, a pre-fabricated frame module 182 defining an openspace 184 is schematically depicted. In the context of the presentinvention, the spatial integrity of the open space 184 is compromisedby: (1) intrusions into the open space 184, and (2) deformation of theopen space geometry. The prefabricated frame module 182 is configuredsuch that the open space 184 maintains a predetermined minimum amount ofspatial integrity in the event of a predetermined horizontal loadexerted on the prefabricated frame module 182 from a horizontal impactto a vehicle in which it may be a part. In other words, theprefabricated frame module is configured such that the quantity andmagnitude of intrusions into the open space do not exceed apredetermined amount, and the size and shape of the open space does notchange more than a predetermined amount, in the event of a predeterminedload to the prefabricated frame module.

More specifically, the prefabricated frame module 182 conforms to apredetermined design, or has a predetermined configuration, that hasbeen engineered, tested, and validated, either physically ormathematically, to comply with a predetermined standard or criterion forthe spatial integrity of the open space 184 in the event of an impact tothe prefabricated frame module 182 or a vehicle component operativelyconnected thereto. The deformation of open space geometry, and magnitudeand quantity of intrusion into the open space, are determined throughsimulations, computer modeling, and crash-testing.

In the embodiment depicted, the prefabricated frame module 182 includesfour open space-defining segments 186, 190. Segments 186 aresubstantially parallel to one another and spaced a distance apart fromone another. Segments 190 are substantially perpendicular to segments186, substantially parallel to one another and spaced a distance apart.Segments 190 are operatively connected to segments 186 such thatsegments 186 and segments 190 define the open space 184 therebetween.

The pre-fabricated frame module 182 preferably includes moduleaugmentation segments 198, 198′ operatively connected to one of the openspace-defining segments 186, 190. Augmentation segments 198 are alignedwith, and substantially abut, segments 190. Augmentation segments 198′are aligned with, and substantially abut, segments 186.

The augmentation segments 198, 198′, in conjunction with the openspace-defining segments 186, 190, maintain the spatial integrity of theopen space 184 in the event of a load exerted on the prefabricated framemodule 182 from an impact to the prefabricated frame module 182 or avehicle of which the prefabricated frame module 182 may be a part. Forexample, the module augmentation segments 198, 198′ may be configured todeform and absorb energy from an impact, or the module augmentationsegments 198, 198′ may be rigid and enhance the structural integrity ofthe prefabricated frame module 182. The module augmentation segments198, 198′ also provide mounting locations for a selection of structuralframe components 202, 206.

In the preferred embodiment, the prefabricated frame module 182comprises hydroformed aluminum tubes with rectangular cross sections.The aluminum tubes are laser welded to each other at joints. However,those skilled in the art will recognize a multitude of materials,forming processes, and joining methods that may be employed within thescope of the claimed invention.

The structural frame components 202, 206 are mountable to thepre-fabricated frame module 182 to form a vehicle chassis structuralframe. The structural frame components 202, 206 depicted are formed fromhydroformed aluminum tubes having rectangular cross sections and weldedto one another. Structural elements 202 define open spaces 210 whereincertain vehicle chassis components may be located. Similarly, structuralelements 206 define cavities 214 wherein other vehicle chassiscomponents may be located. Structural frame components 202 have a lengthL.

FIG. 23, wherein like reference numbers refer to like components fromFIGS. 1-4 and 22, is a schematic depiction of a vehicle chassis 10 ghaving structural frame 11′. The pre-fabricated frame module 182partially defines, and forms a portion of, the structural frame 11′.Structural frame components 202, 206 are operatively connected to theprefabricated frame module 182 to further define the structural frame11′. The frame components 202, 206 are mounted to the pre-fabricatedframe module 182 such that the structural frame 11′ has a shape and sizeincluding length L_(frame). Segments 190 form the forward and rearwardbounds of the open space 184, and segments 186 form the lateral boundsof the open space 184.

The open space 184 provides a protected area in which sensitive andcritical chassis components are placed or packaged. In the embodimentdepicted in FIG. 23, the energy storage system 69, including thecompressed gas storage tanks 121, is mounted with respect to thestructural frame 11′ such that it is at least partially located withinthe open space 184. The steering control unit 99, braking control unit108, and energy conversion system control unit 128 are also mounted withrespect to the structural frame such that they are at least partiallylocated within the open space 184. Other components, such as theelectric motor 127, steering system 81, and HVAC components 218 aremounted to frame components 202, 206 such that they are at leastpartially located within open spaces 210 or cavities 214. A set ofwheels 73, 75, 77, 79 is operatively connected to the chassis 10 g viathe suspension system 71.

The pre-fabricated frame module 182 may be advantageously used in avariety of vehicle chassis frame configurations without modification,reducing engineering resources expended on each frame configuration byproviding a pre-engineered protected area for critical and sensitivechassis components. Referring to FIG. 24, wherein like reference numbersrefer to like components from FIGS. 22 and 23, a second vehicle chassis10 g′ having structural frame 11″ is schematically depicted. The vehiclechassis structural frame 11″ includes a pre-fabricated frame module 182substantially identical to the pre-fabricated frame module of FIGS. 22and 23, and a selection of structural frame components 202′, 206.Structural frame components 202′ are differently shaped and dimensionedfrom structural frame components 202 of FIGS. 22 and 23, resulting inthe second vehicle chassis frame 11″ having a shape and size differentfrom the shape and size of the vehicle chassis structural frame 11′ ofFIG. 23. Specifically, structural frame components 202′ have length L′,which is longer than length L, and structural frame 11″ has lengthL_(frame)′, which is longer than length L_(frame). The energy conversionsystem 69, steering control unit 99, braking control unit 108, andenergy conversion system control unit 128 are mounted to the structuralframe 11″ such that each is at least partially located within the openspace 184.

FIGS. 25-31 are schematic depictions of alternative embodiments of thepre-fabricated frame module. Referring to FIG. 25, wherein likereference numbers refer to like components from FIGS. 22-24,prefabricated frame module 182A includes augmentation segments 222 thatare parallel to segments 190 and operatively connected to twoaugmentation segments 198′. Augmentation segments 222 are configured toreceive an impact load between, and transfer the load to, augmentationsegments 198′.

Referring to FIG. 26, wherein like reference numbers refer to likecomponents from FIGS. 22-25, prefabricated frame module 182B includesaugmentation segments 226 that are parallel to segments 186 and are eachoperatively connected to two augmentation segments 198. Augmentationsegments 226 are configured to receive an impact load between, andtransfer the load to, augmentation segments 198.

Referring to FIG. 27, wherein like reference numbers refer to likecomponents from FIGS. 22-26, prefabricated frame module 182C includesaugmentation segments 230 that extend from the midpoints of segments 186outwardly from the open space 184 to augmentation segment 226. Referringto FIG. 28, wherein like reference numbers refer to like components fromFIGS. 22-27, prefabricated frame module 182D includes augmentationsegments 222 and 230. FIG. 29, wherein like reference numbers refer tolike components from FIGS. 22-28, schematically depicts prefabricatedframe module 182E having augmentation segments 222, 226, 230.

Referring to FIG. 30, wherein like reference numbers refer to likecomponents from FIGS. 22-29, yet another embodiment of the prefabricatedframe module 182F is schematically depicted. Prefabricated frame module182F defines a plurality of open spaces 184, 184A, 184B, 184C. Framecomponents 233 are attachable to prefabricated frame module 182F to forma vehicle chassis structural frame.

Referring to FIG. 31, a method of advantageously employingpre-engineered frame portions to assemble vehicle chassis havingdifferent sizes or shapes is schematically depicted. The methodcomprises assembling a first vehicle structural frame 237. The firstvehicle structural frame has a first frame portion that defines a firstopen space, partially defines the first vehicle structural frame, andhas a predetermined configuration such that the first open spacemaintains a predetermined amount of spatial integrity in the event of aload exerted on the first frame portion from an impact to the firstframe portion or to a vehicle component operatively connected thereto.The first vehicle structural frame also has a first selection of atleast one frame component that further defines the first vehiclestructural frame and is operatively connected to the first frame portionsuch that the first vehicle structural frame has a first shape and size.

The method also includes assembling a second vehicle structural frame241. The second vehicle structural frame has a second frame portionsubstantially identical to the first frame portion that defines a secondopen space, partially defines the second vehicle structural frame, andhas a predetermined configuration such that the second open spacemaintains a predetermined amount of spatial integrity in the event of aload exerted on the second frame portion from an impact to the secondframe portion or to a vehicle component operatively connected thereto.The second vehicle structural frame also includes a second selection ofat least one frame component further defining the second vehiclestructural frame and operatively connected to the second frame portionsuch that the second vehicle structural frame has a second shape andsize. The second shape is different from the first shape, or the secondsize is different from the first size.

The first and second frame portions are preferably prefabricated framemodules. Accordingly, the method may further include maintaining aninventory having a plurality of substantially identical prefabricatedframe modules 245. The first frame portion and the second frame portionare then prefabricated frame modules taken from the inventory.

The method may further comprise assembling a first vehicle chassis 249.The first vehicle chassis includes the first vehicle structural frame, afirst set of at least three wheels rotatably mounted with respect to thefirst vehicle structural frame; a first steering system, a first brakingsystem, a first energy conversion system, and a first energy storagesystem. The first steering system, first braking system, and firstenergy conversion system are mounted with respect to the first vehiclestructural frame and operatively connected to at least one of the atleast three wheels in the first set. The first energy storage system isoperatively connected to the first energy conversion system and mountedwith respect to the first vehicle structural frame. At least one of thefirst energy conversion system, first energy storage system, firststeering system, and first braking system is at least partially locatedwithin the open space of the first frame portion.

The method may further comprise assembling a second vehicle chassis 253.The second vehicle chassis includes the second vehicle structural frame,a second set of at least three wheels rotatably mounted with respect tothe second vehicle structural frame, a second steering system, a secondbraking system, a second energy conversion system, and a second energystorage system. The second steering system, second braking system, andsecond energy conversion system are mounted with respect to the secondvehicle structural frame and operatively connected to at least one ofthe at least three wheels in the second set. The second energy storagesystem is operatively connected to the second energy conversion systemand mounted with respect to the second vehicle structural frame. Atleast one of the second energy conversion system, second energy storagesystem, second steering system, and second braking system is at leastpartially located within the open space of the second frame portion.

In certain circumstances it may be advantageous for the first energyconversion system and the second energy conversion system each toinclude a fuel cell, and for the first energy storage system and thesecond energy storage system to include at least one compressed gasstorage tank configured to store hydrogen. In the preferred embodiment,the first steering system, first braking system, first energy conversionsystem, second steering system, second braking system, and second energyconversion system are responsive to nonmechanical control signals.

FIG. 31 depicts yet another method for advantageously employingpre-fabricated frame modules. The method comprises providing a firstvehicle structural frame 257. The first vehicle structural frameincludes a first frame portion that defines a first open space and afirst selection of at least one frame component operatively connected tothe first frame portion such that the first vehicle structural frame hasa first shape and size. The first frame portion has a predeterminedconfiguration such that the first open space maintains a predeterminedamount of spatial integrity in the event of an impact load to the firstframe portion or to a vehicle component operatively connected thereto.

The method also comprises providing a second vehicle structural frame261. The second vehicle structural frame includes a second frame portionthat is substantially identical to the first frame portion and thatdefines a second open space. A second selection of at least one framecomponent is operatively connected to the second frame portion such thatthe second vehicle structural frame has a second size and shapedifferent from the first size and shape.

The method may also comprise assembling a first vehicle chassis 249 andassembling a second vehicle chassis 253. The first vehicle chassisincludes the first vehicle structural frame, a first set of at leastthree wheels rotatably mounted with respect to the first vehiclestructural frame, a first steering system, a first braking system, afirst energy conversion system, and a first energy storage system. Thefirst steering system, first braking system, and first energy conversionsystem are mounted with respect to the first vehicle structural frameand operatively connected to at least one of the at least three wheelsin the first set. The first energy storage system is operativelyconnected to the first energy conversion system and mounted with respectto the first vehicle structural frame. At least one of the first energyconversion system, first energy storage system, first steering system,and first braking system is at least partially located within the openspace of the first frame portion.

The second vehicle chassis includes the second vehicle structural frame,a second set of at least three wheels rotatably mounted with respect tothe second vehicle structural frame, a second steering system, a secondbraking system, a second energy conversion system, and a second energystorage system. The second steering system, second braking system, andsecond energy conversion system are mounted with respect to the secondvehicle structural frame and operatively connected to at least one ofthe at least three wheels in the second set. The second energy storagesystem is operatively connected to the second energy conversion systemand mounted with respect to the second vehicle structural frame. Atleast one of the second energy conversion system, second energy storagesystem, second steering system, and second braking system is at leastpartially located within the open space of the second frame portion.

In certain circumstances it may be advantageous for the first energyconversion system and the second energy conversion system each toinclude a fuel cell, and for the first energy storage system and thesecond energy storage system to include at least one compressed gasstorage tank configured to store hydrogen. In the preferred embodiment,the first steering system, first braking system, first energy conversionsystem, second steering system, second braking system, and second energyconversion system are responsive to nonmechanical control signals.

As set forth in the claims, various features shown and described inaccordance with the different embodiments of the invention illustratedmay be combined.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the scope of the invention within the scope of the appendedclaims.

1. A vehicle chassis comprising: a structural frame, the structuralframe including: a frame portion partially defining the structuralframe, defining an open space, and having a predetermined configurationsuch that the open space maintains a predetermined amount of spatialintegrity in the event of a horizontal impact to the vehicle chassis;and at least one structural frame component operatively connected to theframe portion and further defining the structural frame.
 2. The vehiclechassis of claim 1, further comprising: at least three wheels rotatablymounted with respect to the structural frame; an energy conversionsystem mounted with respect to the structural frame and operativelyconnected to at least one of the at least three wheels; a steeringsystem mounted with respect to the structural frame and operativelyconnected to at least one of the at least three wheels; a braking systemmounted with respect to the structural frame and operatively connectedto at least one of the at least three wheels; and an energy storagesystem operatively connected to the energy conversion system and mountedwith respect to the structural frame; wherein at least one of the energyconversion system, energy storage system, steering system, and brakingsystem is at least partially located within the open space.
 3. Thevehicle chassis of claim 2, wherein the frame portion is a prefabricatedmodule.
 4. The vehicle chassis of claim 3, wherein the prefabricatedmodule includes a plurality of segments defining the open spacetherebetween, and at least one augmentation segment operativelyconnected to at least one of the plurality of segments defining the openspace; and wherein the at least one structural frame component ismounted to the at least one augmentation segment.
 5. The vehicle chassisof claim 3, wherein the prefabricated module is at least partiallyformed by hydroforming.
 6. The vehicle chassis of claim 2, wherein thebraking system and the energy conversion system are responsive tonon-mechanical control signals.
 7. The vehicle chassis of claim 2,wherein the energy conversion system includes a fuel cell.
 8. Thevehicle chassis of claim 7, wherein the energy storage system isconfigured to store hydrogen.